Manufacturers of food products and beverages for human consumption typically package the beverage or food product. A variety of substances may be used to provide packaging for the products, including, but not limited to, plastics, aluminum, and glass. As a specific example, soft drinks and other beverages typically are packaged in bottles formed from polyethylene terephthalate, otherwise known as "PET bottles." However, other plastics are also well known to the beverage and food packaging industries for use as containers for food and beverage products.
Current practice in the industry, and in particular for the packaging of soft drinks, is to rinse PET bottles and aluminum beverage cans with municipal water prior to filling the bottle with a soft drink. The use of hot water or chemical disinfectants typically has not been considered suitable for rinsing PET bottles and aluminum beverage cans prior to filling because hot water or disinfectants could chemically or physically alter the characteristics of a PET bottle or an aluminum beverage can liner. Such alterations could render the bottles or cans unsuitable for containing beverages, or adversely affect the quality or taste of the beverage, or render the beverage unsuitable for human consumption.
Various devices and processes have been proposed for sanitizing containers such as bottles and cans by contact with an ozonated rinse water. Ozone is highly reactive and is an effective oxidizing agent for sanitizing containers. Ozonated rinse water has the advantage over untreated rinse water of effectively removing microbes and other contaminants without changing the chemical or physical nature of the container. For example, Silberzahn U.S. Pat. No. 4,409,188 proposes a device for sterilizing containers that comprises a rotatable immersion wheel for immersing the containers in a bath of ozone and water. Numerous other devices using ozone as a sanitizing agent have also been proposed.
Hughes U.S. Pat. No. 5,106,495 proposes a portable water purification device that uses ozone as a treatment agent. Water in a tank is circulated by a pump through a venturi where ozone is injected into the water, which is then returned to the tank.
Burris U.S. Pat. No. 5,082,558 proposes a contact lens purification system in which sensors detect the concentration of ozone in the treatment liquid, and a controller acts responsibly to the sensor to control the residence time of the lenses in the system in response to the concentration of ozone.
McConnell et al. U.S. Pat. No. 4,795,497 proposes a method and a system for the fluid treatment of semiconductor wafers in a sequence of fluids and uses a closed fluid recirculation loop and a means for holding the wafers in the fluid flow path. In one embodiment, ozone is bubbled through the treatment fluid to enhance cleaning.
In spite of these previous devices and methods for using ozone as a sterilizing or cleaning agent, the food and beverage industry, and in particular the soft drink industry, still relies on municipal water supplies for rinsing PET containers and aluminum cans prior to filling with soft drink or other beverages such as fruit juice based beverages and sport drinks. The rinse water typically is not recirculated, resulting in the run off of thousands of gallons of waste water and the high costs of operation associated with such a great use of municipal water supplies.
The PET bottles stick together due to static electrical charges and operator personnel sometimes apply additional quantities of food grade lubricants to the bottle handling equipment to compensate. The lubricants stick to the bottles and often are not substantially removed prior to filling with beverage. Increased use of these lubricants can lead to undesirable increased biological and chemical oxygen demand in waste water and causes problems in the plant sewer discharge and increases the cost of sewer discharge.
Copending patent application U.S. Ser. No. 07/986,055, which was filed on Dec. 7, 1992, now U.S. Pat. No. 5,368,815 and is entitled "Process and Apparatus for Sanitizing Articles," describes an apparatus and process for using ozonated water for sanitizing various articles, including PET bottles for the soft drink industry. Subsequently, it was recognized that more debris appeared to be removed from PET bottles and other articles such as aluminum beverage cans with ozonated rinse water than was previously removed with municipal water supplies and that the problem of food containers sticking together was reduced. Static electrical charges associated with the food containers were substantially eliminated by application of ozonated water.